Permanent Magnet Rotor Assembly for Low-Harmonic Elevator Motors
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Solution Overview
Problem
Sintered magnets in elevator motors generate harmonics, causing noise and vibration, and existing bonding methods are inefficient.
Innovation Solution
A permanent magnet motor design featuring a rotor with a support member and magnet units composed of materials with varying remanence, arranged to mimic a sinusoidal magnetic field distribution, using anisotropic sintered and isotropic bonded magnets, and a manufacturing method involving curling and magnetization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If sintered magnets are used in the rotor, then the motor can generate sufficient magnetic field strength, but harmonics are generated causing noise and vibration
Solution Approach 1:
The magnet units have non-uniform remanence distribution along the circumferential direction, with a first portion having greater remanence than second portions on both sides. This local variation in magnetic properties creates a sinusoidal-like magnetic field distribution, reducing harmonics while maintaining sufficient magnetic field strength for motor operation.
Solution Approach 2:
The invention changes the remanence parameter distribution of the magnets from uniform to non-uniform. By configuring magnet units with varying remanence values (first portion with greater remanence, second portions with lesser remanence), the magnetic field distribution is optimized to reduce harmonics and vibration while maintaining operational performance.
2Ease of manufacture
If traditional bonding methods are used to attach magnets to the rotor, then assembly is simplified, but bonding efficiency and reliability are insufficient
Solution Approach 1:
The rotor magnetic system is segmented into multiple magnet units, each with specific remanence characteristics. This segmentation allows for optimized magnetic field distribution while maintaining manageable assembly processes. The support member structure provides a systematic framework for attaching these segmented magnet units.
Solution Approach 2:
The magnet units combine materials with different remanence properties (first material with greater remanence, second material with lesser remanence) to create composite magnetic structures. This composite approach optimizes both the magnetic performance and the bonding characteristics, improving reliability while maintaining ease of manufacture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Reduces harmonics, noise, and vibration, while simplifying assembly and lowering costs by optimizing magnetic field distribution and material usage.
Implementation Method 1
each magnet unit comprising: a first portion made of a first material and second portions made of a second material located on both sides of the first portion in a circumferential direction, where the first portion has a greater remanence than that of the second portion
Data Source
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AI summary
The present invention provides an elevator system, a permanent magnet motor therefor, and a manufacturing method for a permanent magnet motor. The permanent magnet motor comprises: a stator; and a rotor coupled to the stator, wherein the rotor comprises a rotor shaft and a permanent magnet assembly mounted to the rotor shaft, the permanent magnet assembly comprising: a support member; and a plurality of magnet units attached to the support member along a circumference of the support member, each magnet unit comprising: a first portion made of a first material and second portions made of a second material located on both sides of the first portion in a circumferential direction, where the first portion has a greater remanence than that of the second portion. The device and method according to the embodiments of the present invention can reduce the cost of permanent magnet motors.